Abstract: In order to realize the gravity convey of high concentration backfill slurry of aeolian sand at 15 times line, on the basis of the design of filling pipeline and the calculation and analysis of slurry critical velocity in Yuyang Coal Mine, the industrial test on convey by high density slurry backfill pipeline was carried out.The calculation and test results show that the high density aeolian sand backfill slurry has good fluidity, and the fluidity will decrease obviously when the slurry mass fraction (the ratio of solid material mass to slurry mass) exceeds 72%, the upper limit of the concentration of the filling slurry is 75% if it is to be conveyed by gravity; the critical velocity of slurry convey in Yuyang Coal Mine is 1.19 m/s and operating velocity is 4.19 m/s, which is 3.5 times of the critical velocity, the maximum conveying capacity of backfill pipeline of 396 m³/h, and the pipeline conveying of slurry has high reliability, the great times line gravity convey of high density backfill slurry with aeolian sand as aggregate is achieved.